PSO Algorithm For Optimum Design Of Absorbing Material And Study Of Parameters Reconstruction

Particle swarm optimization(PSO) algorithm is a self-organizing evolutionary computation technique based on the movement of swarms. Because it can resolve complex optimization tasks effectively, PSO algorithm is developing very fast in the past few years, and has been applied in image disposing, multi-objection optimization and electromagnetism fields. This paper study PSO algorithm, and discuss control parameters in algorithm how to influence the search performance. PSO algorithm and transmitting matrix algorithm are applied to the reconstruction of electromagnetism parameters of medium. Because of the disadvantages, such as low efficiency and poor accuracy when PSO algorithm optimizes complex and multi-extremum function, two modified particle swarm optimization algorithms are proposed. Numerical value results and examples prove that modified algorithms are superior to the standard algorithm.In order to achieve absorbing electromagnetic wave and shielding effectiveness, absorbing materials of concrete is lossy in electromagnetic. This paper educe computation formula of permeating depth, wavelength, reflection and transmission coefficient when electromagnetic wave propagates in the lossy medium, and analyses the conception about matching impedance. Two keys about the design of absorbing material are discussed: attenuation and matching characteristic. PSO algorithm is used to compute electromagnetic parameters and depth of two layered media, when concrete media can achieve absorbing electromagnetic wave and shielding effectiveness. A soft about the design of absorbing material is developed. This soft is easy to use to the user.Because absorbing material usually is composite medium, the configuration of absorbing material must measure and extract equivalent electromagnetic parameters of composite media, to achieve the result of optimum design. The Nicolson-Ross-Weir, NRW, of electromagnetic parameters extraction, which is a part of microwave measuring, has been thirty years since it was invented. The NRW formula of electromagnetic parameters reconstruction when the medium is in rectangle wave-guide and free space are educed. The method is summarized. The difference about two cases is discussed. Using FDTD and transmitting matrix algorithm, the scattering parameters of medium in rectangle wave-guide and free space are computed, and electromagnetic parameters are extracted. The resonance problem in NRW is analysed. At last, the effective electromagnetic parameters of the composite media are reconstructed by two methods: PSO algorithm and NRW. The results of two methods compared with experience method are accurate.